Water Wisdom

Royal Society report reviewing how spilled oil reacts in water 

is helping enhance industry's water knowledge

This article appears in the March issue of Oilweek magazine.

By Peter McKenzie-Brown

The year 2010 was a watershed for industry people who specialize in oil spill prevention and recovery. BP oversaw management of the biggest blowout in history. Well control and cleanup cost BP US$54 billion, plus US$18.7 billion to settle other claims. These events coincided with an Enbridge pipeline spill. Though a far smaller catastrophe, that spill became history’s most expensive oil spill clean-up operation.

Also in that year, the National Energy Board gave conditional approval for Enbridge to construct its Northern Gateway pipeline. As one of its conditions, though, the regulator instructed the company to establish a research program into the behaviour and cleanup (including recovery) of oils spilled in watery environments.

This reflected the newsworthiness of the two big spills. However, it also recognized the fact that, although oil spills are rare, when y happen they become hot-button issues in the news. Coverage of these worst-on-record events made it clear that, no matter what precautions the industry takes, oil does spill into streams, lakes and the sea.

The NEB condition prompted CAPP and the Canadian Energy Pipeline Association to ask the Royal Society of Canada to supervise a peer-reviewed study into the accidental release of oil into water and wetlands. The seven panel members had world-class credentials, and represented universities and scientific organizations from Canada, America and Australia. The researchers completed and released the report – it bears the yawning title Behaviour and Environmental Impacts of Crude Oil Released into Aqueous Environments – in less than two years.

The chair: Kenneth Lee, the Canadian oil spill recovery expert who chaired the project, is director of Oceans and Atmosphere for the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Perth, Australia. He left Canada four years ago after seeing his federal research lab in Dartmouth, N.S downsized in a budget cut – even though his experience was such that he played a role in mitigating the 2010 Deepwater Horizon disaster.

As a scientist involved in the development and application of oil spill counter-measures, US Government agencies had asked him to work with a science team monitoring  the effectiveness and potential environmental impacts of the clean-up of the 2010 Deepwater Horizon oil spill disaster in the Gulf of Mexico. “I witnessed how the spill affected the region’s environment and the surrounding local communities,” he told his audience in Calgary.

“In the past, industry-research partnerships focused on improving production technologies and solutions,” he wrote by way of introducing himself to his CSIRO colleagues. However, that has changed. “Our focus for oil and gas research now includes environmental, economic and social factors, including risk assessments for regulatory approval, exploration, production, transportation, decommissioning, and emergency response to spills and mitigation.”

Even though Lee had pulled up stakes and moved to Australia, his peers asked him to chair Canada’s oil spill study. Last November he presided over the release of the extensive report (it’s available online) at a talk to industry specialists.

“Do we know enough about how crude oils behave when released into fresh waters, estuaries or oceans to develop effective strategies for spill preparedness, spill response and remediation?” he asked. “What are our gaps in knowledge, and how should research inform policy, regulation and practice?” he asked. Briefly, those were the questions the researchers set out to answer.

Cutting to the chase: “Leading experts on oil chemistry, behaviour, and toxicity reviewed the science relevant to potential oil spills into Canada’s lakes, waterways, wetlands, and offshore,” Lee said. The task force examined the impacts of spills and oil spill responses for everything from pentanes and light oil to bitumen and dilbit and other unconventional oils. It surveyed scientific literature and key reports and oil spill case studies. They consulted industry, government, and environmental stakeholders. While most of the spills they studied took place in Canada, some were out of the country – for example, the accidental release of dilbit into a tributary of Michigan’s Kalamazoo River from a two-metre rupture in an Enbridge pipeline. Cleanup took two years, and cost US$765 million.

Each crude oil type has its own chemical “fingerprints,” Lee said, and those fingerprints determine how readily spilled oil spreads, sinks and disperses, how it affects aquatic critters and wildlife, and how long it takes for biodegradation of the oil to start. For the most part, oil’s impact on water depends on weather and waves, and how quickly clean-up operations begin.

The result is technical coverage of saltwater straits, freshwater lakes, running rivers and dense wetlands. Each is home to distinctive geologic features, but also to microorganisms that can transform oil as it spills and spreads. Those microscopic bugs degrade different oil types in a variety of ways, and their impact is often an important part of oil spill cleanup strategies. “Sunlight, wind, waves, and weather conditions can physically and chemically transform a spill,” the report says. “These changes to the chemistry of oil are crucial factors affecting how spilled oil spreads, affects aquatic organisms and people, or lingers in the environment.”

Oil spills are  infrequent, according to the report, “and the probability of spills decreases with increasing spill size.

Despite the relative infrequency of crude oil spills into water, they can have big impacts economically, and from the perspectives of human health, safety and the environment. These realities raised many questions, and they demanded study.

Biodegradation: As technical as its title, the report set out to answer six questions, and uses 240,000 words to do so. Here is a summary of its first three conclusions.

To begin, the science is limited to a large degree because of the chemical degradation that takes place as oil in water weathers. However, “the initial and ultimate fate” of all oil types is strongly affected by season and weather. “The lighter the oil, the more it is affected by spreading and evaporation and the easier it is to treat effectively,” says the report. These processes slow down as the oil gets heavier. Heavy oil and bitumen-type oils, which have fewer water-soluble components, are more resistant to evaporation and biodegradation. Thus, “their potential long-term damage to the environment, waterfowl and fur-bearing animals is greater,” and cleanup is extremely difficult.

Another key question was how the different forms of oil affected different water ecosystems. Most of the creatures living in water are victims of some degree of habitat destruction from oil spills but the largest group of studies available had to do with the impact of spills on fish. Many of the studies available concerned fish, but in this case, spills of light oil are the cause. 

“Observed fish kills are typically brief and localized because of the rapid loss of [acutely lethal low molecular weight oil components] through dilution and weathering,” the authors wrote. They cautioned, however, about extensive fish mortalities “observed in rivers where a point source of oil was rapidly transported downstream before significant weathering occurred.”

The microbiologists on the team wanted to know how these ubiquitous creatures affect the properties of spilled oil, its persistence and its toxicity. Once again, they reported that light oils are more biodegradable than heavier oils and leave lighter residues. Smaller proportions of heavy crudes are readily biodegradable, and their residues persist in the environment even after cleanup. Ironically, they observe that, an area which has been the site of previous spills may begin biodegradation of a new spill quite quickly. The idea is that microbes in existing oil residues would rapidly begin to multiply, consuming the new oil. That said, the researchers worried about the impact of microbial processes on diluted bitumen. The alkalinity of dilbit could kill off some forms of microbe.

Oil spill response: Behind the endless science in this report, of course, is the technical information needed to contribute to oil spill containment and recovery practice, and the balance of the report focuses in that area. After urging further biodegradability studies, the report discusses the use of oil dispersants for spill response, and discusses the use of mathematical tools to optimize doses, logistics and operations used to apply them. It also argues for “more effective and eco-friendly” dispersants.

What’s more, the oil spill recovery techniques in use today – for example, the use of booms, in-situ burning, skimming, dispersion and bioremediation – have a lot of limitations. They aren’t easily adaptable for cold waters and Arctic environments, for example. Among a truckload of other recommendations, the researchers recommend more field trials to advance spill response practices – “especially for subsurface blowouts, Arctic oil spills and freshwater shorelines.”

And in the spirit of good science, of course, they call for new studies to fill in the gaps, identifying seven areas where industry, government and academic institutions need to do more work. New work is coming from many research teams and funding agencies. As importantly, it is leading to technologies and other approaches to watershed management that reduce water-body contamination.

Take the case of operations that develop resources through fracking. 

President of the Canadian Society for Unconventional Resources Kevin Heffernan describes many ways his industry – a big water user – is “greening” its use of water. “You can reduce water use by injecting the water where it’s needed only, and there are technologies like the ‘sliding sleeve’ which enables you to inject water, chemicals and other materials only where you will get maximum production.”

Eric Schmelz – a vice president of NCS Multistage, which deploys this technology –providing precise positioning in the horizontal wellbore can “reduce by up to 50 percent the amount of fluid needed for fracking using the old methods. More typically, it involves a 30 to 40 percent reduction.”

A smattering of advocates: Consider a study sponsored by WaterSmart, a Calgary-based not-for-profit focused on efficient water consumption, and CCEMC, an industry-funded corporation which helps finance environment-related science. “Alberta’s social, economic and environmental history and heritage is directly tied to its water resources.” Although powered by hydrocarbons, “Alberta’s economy runs on water,” it says. “Water availability constrains and challenges economic and population growth throughout the province.”

WaterSmart’s executive director, Kim Sturgess, says good water management is less about technology, more about cooperation among the people who work and live in a given area. “The watershed management plan, and cooperation among the communities that need the water and use it – those are the key concerns that I have.” Everyone in the province has a stake in clean water, and “we need to work together to sustain the resiliency of Alberta’s water supplies and the communities (including industry) that need them.” 

She also worries that the water used to produce the oilsands comes mostly from underground aquifers. “Groundwater aquifers are not well understood in this province,” she says. “There are pockets in Alberta where the groundwater is well known but overall that is not the case.” She is especially concerned about the management of the downhole aquifers tapped for SAGD operations.

According to Brett Purdy of Alberta Innovates, a provincial think-tank, one consortium is testing a zero-liquid-discharge water treatment system. Now under construction, the test unit will produce “solid salt rather than liquid brine” from contaminated or processed water at a SAGD facility. Compared to conventional treatment, “the pilot is likely to discharge less wastewater, and withdraw less freshwater from nearby reservoirs,” he says.